‘Coeliac disease is a proven medical condition while vitamin D is notoriously difficult to establish.

‘Having a situation where we’re comparing the sort of ongoing disease with vitamin D deficiency, it just doesn’t seem right.

‘There’s so much to take on with the STPs, the problem is that short term decisions are made.’

The digestive condition means the small intestine becomes inflamed and is unable to absorb nutrients, due to an adverse reaction to gluten.

Data compiled by the charity reveals 39 CCGs in England have stopped prescribing food, except for in exceptional circumstances, such as for young children or deprived patients.

Decisions made to stop providing the food have been made in Croydon, Gloucestershire, Whitby and Harrogate.

It means a postcode lottery has developed, with some neighbouring counties offering differing levels of support.

Around 150,000 people in the United Kingdom have been diagnosed with coeliac disease, according to research in 2014.

A further 500,000 extra could be living in the UK undiagnosed, Ms McGough said.

‘Coeliac disease is not a choice, it’s a serious medical condition, when the body’s antibodies attacks its own body when gluten is eaten,’ Ms McGough added.

‘By consuming gluten it activates the disease process.

‘If you continue to eat gluten then essentially there will be a risk of complications with coeliac disease and then there are problems of osteoporosis, due to malabsorption of calcium, then there’s a rare risk of cancer.

‘We have got so far in being able to identify people with coeliac disease and provide then with the treatment that we don’t want to go back to a time when people were very, very poorly as a result of coeliac disease when it can be prevented by simple measures.

‘We understand the cost pressures for the NHS and obviously want to try to work with the NHS to make the cost efficiencies.’

In the Vale of York CCG, coeliac patients are to be provided with vouchers to help pay for the extra costs involved with gluten-free food, Ms McGough added.

A former clinical director at Lewisham Hospital who has more than 40 years of experience in the NHS, Dr O’Sullivan, said: ‘The more restrictive the health service becomes, we’re going to make it more difficult for people.

‘You won’t be able to have two cataract operations, you’ll have one eye not the other, you can have one hearing aid but not two.

‘The more the waiting lists goes up for hip and knee replacements - certainly they’re making changes so that people who can will go privately.’

All hospitals and CCGs are expected to have policies for cost-effective and clinically-required treatments.

Clinicians have said more gluten-free products are now available in the shops, while Coeliac UK campaigners say gram for gram, gluten-free bread is six times more expensive.